Vein Scanner

ABSTRACT

A portable vein viewer apparatus may be battery powered and hand-held to reveal patient vasculature information to aid in venipuncture processes. The apparatus comprises a first laser diode emitting infrared light, and a second laser diode emitting only visible wavelengths, wherein vasculature absorbs a portion of the infrared light causing reflection of a contrasted infrared image. A pair of silicon PIN photodiodes, responsive to the contrasted infrared image, causes transmission of a corresponding signal. The signal is processed through circuitry to amplify, sum, and filter the outputted signals, and with the use of an image processing algorithm, the contrasted image is projected onto the patient&#39;s skin surface using the second laser diode. Revealed information may comprise vein location, depth, diameter, and degree of certainty of vein locations. Projection of vein images may be a positive or a negative image. Venipuncture needles may be coated to provide visibility in projected images.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/804,506, filed Jul. 22, 2010, which claims priority on U.S.Provisional Application Ser. No. 61/271,587, filed on Jul. 22, 2009,with the disclosures of each being incorporated herein by reference.

BACKGROUND OF THE INVENTION

Drawing blood and administering intravenous medication using medicaldevices including but not limited to catheters are common medicalprocedures, but conventional methods to perform these procedures haveseveral limitations. First a vein must be found. Conventional methods oflocating an appropriate vein or artery include restricting the bloodsupply to the location of the body so that the blood pressure in thatarea is greater, which results in the patient's veins becoming morevisible. This is often accomplished by the use of a temporarytourniquet, which can result in extreme discomfort to the patient. Evenafter the temporary tourniquet is applied and certain veins are exposed,a medical professional may still not be able to find an appropriatevein. This problem can occur more readily in elderly patients andpatients with low blood pressure. Thus, there is a need for anon-invasive method for locating veins.

SUMMARY OF THE INVENTION

The present invention is directed towards a portable hand-held medicalapparatus that uses infrared light to detect veins beneath the skin,then illuminating the position of the veins on the skin surface directlyabove the veins using visible light. When the apparatus is held adistance above the outer surface of the skin, veins appear vastlydifferent than the surrounding tissue, and veins that are otherwiseundetectable because of their depth in the tissue are safely located andmapped on the patient's skin. Vein's will be accessed more readily andwith greater confidence and as such, venipunctures will go more smoothlywhile vasculature shows up clearly on the skin's surface, making it easyto select the best vein to collect a blood sample from or administermedications to. Qualified medical personnel can observe the displayedvasculature to assist them in finding a vein of the right size andposition for venipuncture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the apparatus of the present invention.

FIG. 2 is a perspective view of a charging cradle for the apparatus ofFIG. 1.

FIG. 3 is a front view of the apparatus of FIG. 1, while being chargedin the cradle of FIG. 2.

FIG. 4 is a perspective view of the apparatus of FIG. 1 being charged inthe cradle of FIG. 2.

FIG. 5 is a side perspective view of the apparatus of FIG. 1,highlighting the buttons and LCD screen of the device of FIG. 1.

FIG. 6 is a bottom view of the apparatus of FIG. 1.

FIG. 7 is an image of a health care professional utilizing the apparatusof FIG. 1 to enhance the vein image of veins in a patient's arm.

FIG. 8 is a Figure illustrating proper angling of the apparatus whenbeing used to enhance the vein image of veins in a patient's arm.

FIG. 9 is Figure illustrating proper centering of the apparatus whenbeing used to enhance the vein image of veins in a patient's arm.

FIG. 10 is a perspective view of the apparatus of FIG. 1, with thebattery cover removed to show the battery compartment.

FIG. 11 is a perspective view of the apparatus showing removal of thebattery cover.

FIG. 12 is a perspective view of the apparatus with the battery coverremoved, exposing the battery when properly installed in the batterycompartment.

FIG. 13 is a perspective view of battery of the apparatus.

FIG. 14 is a series of images identifying different indications the LCDdisplay will provide for battery power levels.

FIG. 15 is a pair of screen shots of the LCD screen utilized for makingconfiguration setting changes.

Table 1 is a list of all of the LCD button icons and theirfunctionality.

FIG. 16 is a series of screen shots of the LCD display used formodifying the default Vein Display Setting.

FIG. 17 is a series of screen shots of the LCD display illustratingchanging of the Display Time-out interval.

FIG. 18 is a screen shot illustrating how to change the BacklightIntensity of the apparatus.

FIG. 19 is a screen shot of the LCD screen used for changing the speakervolume of the apparatus.

FIG. 20 is a series of screen shots showing the steps for labeling ofthe apparatus according to a user's preference.

FIG. 21 is a screen shot illustrating how to change or review thelanguage utilized on the apparatus.

FIG. 22 is a screen shot illustrating how to reset all of the settingsfor the apparatus back to the factory default settings.

FIG. 23 is a perspective view illustrating plugging a USB cable into theback of the apparatus to communicate with a PC, and a screen shotillustrating the LCD screen of the device schematically illustrating theconnection.

FIG. 24 is a screen shot as it would appear on the PC of FIG. 23 whenlooking for the apparatus.

FIG. 25 is a screen shot as it would appear on the PC after theapparatus was detected, and the software running on the PC was checkingto see if the apparatus software was current or needed to be updated.

FIG. 26 is a screen shot as it would appear on the PC, when an apparatusis not detected by the PC.

FIG. 27 is a screen shot illustrating the capability of naming theapparatus or changing the language, and doing so from the PC.

FIG. 28 is a series of screen shots of the PC illustrating the steps inwhich the software of an apparatus is updated.

FIG. 29 illustrates a cradle pack and mounting hardware for use in amedical environment utilizing a series of vein enhancing apparatuses.

FIG. 30 is an exploded view of the apparatus of the present invention.

FIG. 31 shows a bottom perspective view of the bottom section of thehousing.

FIG. 32 shows a top perspective view of the bottom section of thehousing.

FIG. 33 is a top view of the bottom section of the housing.

FIG. 34 is a cross-sectional view of the bottom section of the housing.

FIG. 35 is a bottom view of the bottom section of the housing.

FIG. 36 is an end view of the bottom section of the housing.

FIG. 37 is a top view of the top section of the housing.

FIG. 38 is a side view of the top section of the housing.

FIG. 39 is a bottom view of the top section of the housing.

FIG. 39A is a cross sectional view through the apparatus of FIG. 39.

FIG. 40 is a first section cut through the top section of the housing.

FIG. 41 is a second cross-section through the bottom section of thehousing.

FIG. 42 is an exploded view of the photodiode assembly.

FIG. 42A is a reverse perspective view of the photodiode board in theexploded view of FIG. 42.

FIG. 43 is a top view of the photodiode assembly.

FIG. 44 is a bottom view of the photodiode engine.

FIG. 45 shows a perspective view of the bottom section of the housingwith a portion of the photodiode assembly mounted inside the cavity ofthe bottom section of the housing.

FIG. 46 is a bottom view of the portable apparatus of the presentinvention.

FIG. 47 is a view of the inside of the battery cover.

FIG. 47A is a view of the outside of the battery cover.

FIG. 48A-C is a assembly level block/schematic diagram of the presentinvention

FIG. 49A-B is an additional assembly level block diagram of the presentinvention.

FIG. 50A-B is a schematic of a circuit diagram of the user interfaceboard.

FIG. 51A-B is a schematic of a circuit diagram of the photodiode boardconnection.

FIG. 52 is a schematic of a circuit diagram of the USB chip.

FIG. 53A-B is a schematic of a circuit diagram of the photodiode board.

FIG. 54 is a schematic of a circuit diagram of the battery connectorboard

FIG. 55A-B is a schematic of a circuit diagram of the visible laserdrive.

FIG. 56A-B is a schematic of a circuit diagram of the laser safetyfeature of the present invention

FIG. 57A-B is an additional schematic of a circuit diagram of thephotodiode engine.

FIG. 58A-C is a schematic of a circuit diagram of the speaker of thepresent invention

FIG. 59A-C is an additional schematic of a circuit diagram of thephotodiode engine.

FIG. 60A-B is an additional schematic of a circuit diagram of thephotodiode assembly.

FIG. 61A-B is a schematic of a circuit diagram of a microcontroller ofthe present invention.

FIG. 62A-C is a schematic of a circuit diagram of the power supply ofthe present invention.

FIG. 63A-B is an additional schematic of a circuit diagram of the powersupply and its peripheral connections.

FIG. 64A-B is a schematic of a circuit diagram of the battery managementsystem.

FIG. 65A-B is a schematic of a circuit diagram of the photodiode engine.

FIG. 66A-E illustrates the graphical or symbolic information that may beprojected onto a patient other than just vein imaging.

FIG. 67A illustrates a first arrangement of optical detectors that maybe used for the apparatus.

FIG. 67B schematically illustrates an alternative arrangement of opticaldetectors.

FIG. 67C illustrates a second alternative arrangement for the opticaldetectors.

FIG. 68 illustrates one mechanical arrangement for the scanning mirrors.

FIG. 69 illustrates smoothing of the edges of the scanning mirrors toimprove the high resolution images at smooth video rates.

FIG. 70 illustrates the apparatus illuminating on the skin of a patient,a coated needle that has been inserted beneath the patient's skin.

FIG. 71A illustrates a typical return signal collected from photodiodesof the current invention, with local peaks corresponding to veinlocations.

FIG. 71B represents the same signal of FIG. 71A after differentiation.

FIG. 72 illustrates a few consecutive scan lines crossing a single vein.

FIG. 73 is a graph showing the output power versus the forward currentfor a laser, to illustrate an inflection point.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an apparatus 10 (FIG. 1) that is anopto-electronic device that assists medical practitioners by locatingveins and then projecting an image of those veins directly on apatient's skin. The apparatus may be portable, hand held, and batterypowered. However in an alternative embodiment an external power supplymay be used to power the apparatus. The apparatus operates by usinginfrared light to detect veins beneath the skin, and then illuminatesthe position of the veins on the skin surface directly above the veinsusing visible light. The apparatus 10 may be battery powered, andrechargeable using a cradle 5 (FIG. 2), and may generally be storedtherein (FIGS. 3-4).

The apparatus 10 generally comprises a housing 11, internal circuitry12, keypad 13, display 14, scanner assembly 15, and battery pack 16. Thehousing 11 may generally comprise a top section 17 and bottom section 18as shown in FIG. 30. Although a specific shape for the housing and thetop and bottom sections are shown it will be appreciated that this ismerely a representative example and other configurations are intended tobe included in the invention. The function of the housing 11 is to forexample provide a location to mount the internal circuitry 12, keypad13, display 14, scanner assembly 15, and battery 16. A generalembodiment of the housing will be disclosed, but it will be generallyunderstood that modifications to the housing to accommodate differentinternal circuitry, keypad, display, laser assembly, and battery arewithin the scope of this invention. In addition, if other features aredesired the housing may be modified to include those features.

The housing 11 may be comprised generally of a top section 17 and abottom section 18. FIGS. 31 and 32 show a representation of oneembodiment of the bottom housing section 18 of the housing 11, inperspective views, and which are detailed in FIGS. 33-36. As seen inFIGS. 31 and 32, the bottom housing section 18 generally comprises aleft sidewall 19 and a right sidewall 20, which are connected by a frontwall 22 and rear wall 23. The exterior surfaces of those walls, whichmay be handled by the user, are seen in FIG. 35, while the interiorsurfaces of those walls, which may receive the electronic circuitry andother components, are visible in FIG. 33.

The walls 19-22 may each be angled, and may be so angled simply foraesthetic reasons, or for better handling by a user, or the angling(draft) may be the result of the manufacturing process used to createthe housing bottom section 18, possibly being a casting process, aforging process, or a plastic injection molding process. However, thewalls 19-22 need not be so angled, and the housing bottom section 18 mayalso be manufactured using any other suitable manufacturing process orprocesses, including, but not limited to, machining of the part. One endof the angled walls 19-22 may terminate in a generally flat bottom wall23, to create an internal cavity 24. The generally flat bottom wall 23may transition, using transition wall 25, into another generally flatwall 23A. Wall 23A may be interrupted by a series of internal walls(26A, 26B, 26C, and 26D) extending therefrom and an internal top wall26E connecting those internal side walls, to form a compartment that mayhouse the battery 16. The other end of the angled walls 19-22 mayterminate in an edge 27. Edge 27, at front wall 21 and in the nearbyregions of sidewalls 19 and 20, may be generally planar, but maytransition into edge 27A, which serves as a transition to generallyplanar edge 27B that begins at rear wall 22. Each of the edges 27, 27A,and 27B of the housing bottom section 18 may have a step for receiving acorresponding protruding flange of the housing top section 17, when theyare joined during assembly of the apparatus 10.

In one embodiment, the front wall 21 and sidewalls 19 and 20 of thehousing bottom section 18 may have extending up towards the plane of theedge 27, one or more cylindrical members—a boss 107, which is adapted toreceive mounting screws 106, and may include the use of threaded insertsfor mounting of the housing top section 17 to the housing bottom section18. It will be appreciated that other mounting means may be used,including, but not limited to, the use of a snap closure, or a post andrecess combination with a friction fit therebetween.

The bottom wall 23 of housing bottom section 18 may be provided with twoorifices 28, and 29. On the outside surface of bottom wall 23 there maybe one or more annular recesses 28A and 29A, being concentric toorifices 28 and 29, respectfully, each of which may be used to receive alens 90 (FIGS. 6 and 10).

Protruding inward from the inside of bottom wall 23 may be cylindricalprotrusions 31, and 32. Protrusions 31 and 32 may be concentric withorifices 28 and 29, respectfully, and may be adapted to receive aportion of the photodiode masks 66 and 67 of the scanner assembly 15,which are discussed later.

Mounted inside the battery compartment formed by walls 26A-26E may bethe battery pack 16. The battery pack 16 (FIG. 13) can be any of avariety of models known in the art, but in a preferred embodiment, itmay be rectangular to fit inside the compartment formed by walls26A-26E. One end 16A of the battery pack 16 may be adapted to bereceived by the power connection 95 on the main circuit board (FIG. 30).The battery pack 16 may be secured in the battery compartment by abattery cover 96 which attaches to the bottom section 18 of housing 11.The battery cover 96 may attach to the bottom section of the housing 18in a variety of ways, such as by clips or screws. As seen in FIG. 47,the battery cover 96 may be secured by having a pair of flanges 96Aextending therefrom be received in a pair of slots 34 in the bottomsection 18 of housing 11. FIGS. 62-64 are schematics of circuit diagramswhich demonstrate how the battery pack is connected to the internalcircuitry 12, the scanner assembly 15, and remaining electricalcomponents of the invention.

FIGS. 37-41 show a representation of one embodiment of the top section17 of the housing 11. The housing top section 17 may be formed similarto the housing bottom section 18, and thus may have a top wall 81 fromwhich extends, generally at an angle, a left sidewall 83 and rightsidewall 84, and a front wall 85 and rear wall 86. The front wall 85 andrear wall 86 may extend from the left sidewall 83 and right sidewall 84,respectively, creating an internal cavity 87. FIG. 37 shows the outersurfaces of those walls, while FIG. 39 shows the inner surfaces of thosewalls. The walls 83-86 extend out to a generally planar edge 82, whichmay have a peripheral flange protruding therefrom to mate with therecess of the housing bottom section 18. In one embodiment, housing topsection 17 may have extending down from top wall 81 and walls 83-86,towards the plane of the edge 82, one or more cylindrical members 108,which are adapted to receive mounting screws 106, and may include use ofthreaded inserts. The cylindrical members 108 of the housing top section17 may be positioned to be in line with the corresponding members 107 ofthe housing bottom section 18 to be secured thereto during assembly ofthe scanner 10.

The outer surface of the top wall 81 of the housing top section 17 mayhave a step down into a flat recessed region 81A having an edgeperiphery 81P. That flat recessed region 81A may comprise of an opening91 through to the inside surface, which may be a rectangular opening,and a plurality of shaped orifices 93A, 9313, and 93C. Therectangular-shaped opening 91 may be sized and otherwise adapted toreceive the display 14, which is discussed in more detail hereinafter.The flat recessed region 81A of top wall 81 may receive a display guard92 (FIG. 30), to provide a barrier between the display 14 and theoutside environment. The plurality of shaped orifices 93, which may alsobe correspondingly found in the display guard 92, are adapted to receivea plurality of buttons 77 or other activating means which may be mounteddirectly under the top plate 81 of the housing top section 17. In apreferred embodiment, there are three buttons—a first display button110, a second display button 111, and a power button 112. Buttons110-112 may be any shape practicable, but in a preferred embodiment,display buttons 110 and 111 are elliptical, and button 112 is circular.(Note that a fourth button 113 protruding from the side of the housing,as seen in FIGS. 5 and 30, may also be used to power the apparatus up ordown, as well as accomplish other functions as well).

Alternatively, other means of user input, such as touch screen, touchpad, track ball, joystick or voice commands may replace or augment thebuttons.

The internal circuitry 12 is illustrated in FIGS. 48-65, and can includea main circuit board 43, a user interface board 44, USB chip 46, andspeaker 47. In one embodiment, the main circuit board 43 contains atleast two orifices 48 and 49 which are adapted to receive mountingmember 50 and mounting member 51. Mounting members 50 and 51 may be usedto secure the main circuit board 43 to the heat sink 52. Mountingmembers 50 and 51 may be screws, or pins or any similar type of memberused to secure internal circuitry known in the art. FIG. 48 is aschematic of a circuit diagram of the main circuit board 43 and how itconnects to the remaining components of the present invention.

As seen in FIG. 30, heat sink 52 generally comprises a left sidewall 99,and right sidewall 100, and a front sidewall 104 extending between theleft and right sidewall. In a preferred embodiment heat sink 52 may alsocontain a middle bridge 101 which connects the left sidewall 99 with theright sidewall 100. Extending from the middle bridge and curvingdownwards is a hook member 102. The hook member has an internal cavity103, which is adapted to receive the USB chip 46. On the front sidewall104, and left and right sidewalls 99 and 100, there may be cylindricalmembers 105 that are adapted to receive mounting screws 106, and mayinclude the use of threaded inserts. Mounting members 40 may be used tomount the scanner assembly 15. In one embodiment, mounting members 40may be screws. It will be appreciated that the photodiode assembly maybe mounted by other means.

The heat sink capabilities might be enhanced by a fan or blower arrangedin a way that would direct the air flow onto the heat sink and out ofthe housing. Additionally, a thermodynamic or thermoelectric heat pumpmay be employed between the heat-dissipating portions of the heat sink,to facilitate heat exchange. In a preferred embodiment, a heat shield 80is mounted onto the top surface of the user interface board 44.

Preferably being directly connected the main circuit board 43, is theuser interface board 44. FIG. 50 is a schematic of a circuit diagram ofthe user interface board. The user interface board 44 contains thefirmware which sends a graphic user interface to the display 14, andstores the user's preferences. In one embodiment the interface board 44is directly mounted to the top surface of the main circuit board. In oneembodiment, the display 14 is directly mounted to the user interfaceboard 44, and may be a Liquid Crystal Display (LCD). It will beappreciated to those skilled in the art that an Organic Light EmittingDiode display (OLED) could work equally well. Alternatively, other meansof information delivery may be used, such as lamp or LED indicators andaudible cues. Some of the information that may be delivered to the user,other than the projection of vein images onto a patient's arm, may bevisual cues also being projected on the patient's arm alongside the veinimages, visual cues regarding additional information concerning theveins.

Mounted to the user interface board may be a keypad 13. Keypad 13, asnoted previously, may be comprised of a plurality of control means whichmay include, but is not limited to, a plurality of buttons 77. In apreferred embodiment, there may be three buttons used for controllingthe apparatus—buttons 110-112. Each of these buttons may have a firstend 78 and a second end 79. The first ends 78 of the plurality ofbuttons is adapted to be exposed through corresponding openings in thehousing top section 17, where they may be toggled by the user. Thesecond end 79 of the buttons is adapted to be received by the userinterface board 44.

Also attached to the main circuit board is the USB chip 46. USB chipmounts to the main circuit board 43 at a pin connection, and provides apin connection for speaker 65. The USB chip 46 is preferably mounted tothe bottom surface of the main circuit board.

Also connected to the main circuit board is the scanner assembly 15(FIG. 42). The scanner assembly 15 generally includes a photodiodeengine 53, a photodiode board 54, and a heat pipe 55. In one embodiment,the photodiode engine 53 is directly mounted to the top surface of thephotodiode board 54, by one or more screws 56, 57, and 58. In anotherembodiment, the bottom surface of the photodiode board is mounted to afoam fresen 59. In the same embodiment, the foam fresen 59 is mounted tothe bottom plate of the bottom section. In a preferred embodiment thefoam fresen 59 has an orifice 69 which is adapted to receive the portionof the photodiode engine which houses the display light 62. In apreferred embodiment the foam fresen 59 has a first arcuate cutout 75 atits front end and a second arcuate cutout 76 at its rear end. Arcuatecutouts 75 and 76 provide an arcuate surface for grommets 73 and 74 tobe received.

The photodiode engine comprises a display light 62 (FIG. 44). FIGS. 55,61, and 65 are schematics of circuit diagrams relating to the photodiodeengine and its peripheral connections. The display light 62 may becomprised of at least a red laser 63 and an infrared (IR) laser 64. In apreferred embodiment red laser 63 may be a laser diode emitting light ata wavelength of 642 nm, and an infrared (IR) laser 64 that may emitlight at a wavelength in the near infrared to be at 785 nm. Othercombinations of wavelengths of more than two lasers may be used toenhance both the collection of the vein pattern and the display of thecollected information. Red laser 63 projects an image of the veinpattern on the patient's skin. The laser diode has a wavelength of 642nm, which is in the visible red region, but falls outside the spectralresponse range of photodiodes 60 and 61. Red laser 63 illuminates areaswith no veins, and does not illuminates areas with veins. This resultsin a negative image that shows the physical vein locations.Alternatively, the positive image may be used, where the red laserilluminates the vein locations and does not illuminate spaces betweenveins.

The red laser may be employed to project information other then veinlocations, by means of turning on the laser or increasing its brightnesswhen the laser beam is passing over the brighter parts of graphical orsymbolic information to be projected, and turning off the laser orincreasing its brightness when the laser beam is passing over the darkerparts of graphical or symbolic information to be projected. Suchinformation may include the vein depth, vein diameter, or the degree ofcertainty with which the device is able to identify the vein location,expressed, for example, through the projected line width 501 (FIG. 66(a)), the length of the strokes in a dotted line 502 (FIG. 66( b)), as abar graph 503 (FIG. 66( c)) or a numeric indication 504 (FIG. 66( d)).It may also include user's cues 505 and 506, respectively for optimizingthe position of the device, such as choosing the correct tilt anddistance to the target (FIG. 66( e)).

Vein location and other information may also be displayed by projectionmeans other than scanning laser, through the use of, for example, a DLP(Digital Light Processing) projector, a LCoS (Liquid Crystal on Silicon)micro-projector, or a holographic projector.

Additionally, the firmware of the photodiode board 54 may be programmedto recognize and modify display 14, and projection by the display light62 to represent a needle, catheter, or similar medical device 573 whichhas been inserted beneath a patient's skin and a part of it 573 a is nolonger visible to the naked eye (FIG. 70). The needle or medicalapparatus may be made with, or coated with a material that absorbs orreflects a specified amount of the light from the IR laser 64. Glucoseis one example of a biomedical material which could be used as a coatingto absorb or reflects a specified amount of an IR laser. Photodiodes 60and 61 will detect the difference in reflection and absorption, and thephotodiode board 54 may modify display 14 to show the needle or medicaldevice. The photodiode board 54 may also be programmed to modifyprojection by the display light 64 so that the needle or medical devicewhich has been inserted into the patient's skin is displayed.

More detailed information on the use of the laser light to view theveins can be found in U.S. patent application Ser. No. 11/478,322 filedJun. 29, 2006 entitled MicroVein Enhancer, and U.S. application Ser. No.11/823,862 filed Jun. 28, 2007 entitled Three Dimensional Imagining ofVeins, and U.S. application Ser. No. 11/807,359 filed May 25, 2007entitled Laser Vein Contrast Enhancer, and U.S. application Ser. No.12/215,713 filed Jun. 27, 2008 entitled Automatic Alignment of aContrast Enhancement System the disclosures of which are incorporatedherein by reference.

The photodiode board 54 comprises one or more silicon PIN photodiodes,which are used as optical detectors. In a preferred embodiment,photodiode board 54 comprises at least two silicon PIN photodiodes 60and 61 (FIG. 42A). The field of view (FOV) of the optical detectors ispreferably arranged to cover the entire area reachable by light from IRlaser 64. FIGS. 8 and 10 are schematics of circuit diagrams whichrepresent the photodiode board and its peripheral connections. In frontof these photodiodes 60 and 61 are filters 120 and 121 (FIG. 42A) toserve as an optical filters that transmit infrared light, but absorb orreflect light in the visible spectrum. Mounted to photodiode 60 and 61may be photodiode masks 66 and 67. Photodiode masks 66 and 67 comprise ashaped orifice 68 which is adapted to be received by photodiode 60 and61 respectively. In a preferred embodiment photodiode masks 66 and 67are circular and are adapted to be received by the cylindricalprotrusions 31 and 32 of the housing bottom section 18. The photodiodeboard 54 is further comprised of an orifice 70. The opening 70 may berectangular and adapted to receive the portion of the photodiode enginewhich houses display light 62. In a preferred embodiment the photodiodeboard 54 has a first arcuate cutout 71 at its front end, and a secondarcuate cutout 72 at its rear end. Arcuate cutouts 71 and 72 provide anarcuate surface for grommets 73 to be received.

Other arrangements of optical detectors may be used too. In one possiblearrangement, depicted on FIG. 67( a), the photodiode's field of view(FOV) 510 may be shaped by lenses—Fresnel lenses, curved mirrors orother optical elements 511—in such way that the FOV extent on thepatient's arm becomes small and generally comparable with the size ofthe IR laser spot 512. This reduced FOV is forced to move synchronouslywith the laser spot by virtue of directing the optical path from thepatient's arm to the photodiodes through the same scanning system 513employed for the scanning of the laser beam, or through another scanningsystem, synchronous with the one employed for the scanning of the laserbeam, so the FOV continuously overlaps the laser beam and follows itsmotion. Additional optical elements, such as a bounce mirror 514, mightbe used to align the laser bean with FOV. Such an arrangement isadvantageous in that it enables the photodiodes to continuously collectthe reflected light from the IR laser spot while the ambient lightreflected from the rest of the target generally does not reach thephotodiodes.

Alternatively, the FOV of the photodiodes may be reduced in only onedirection, and routed through the scanning system in such way that itfollows the laser beam only in the direction where the FOV has beenreduced, while in the other direction the FOV covers the entire extentof the laser scan (FIG. 67( b)). Such FOV may be shaped, for example, bya cylindrical lens in front of a photodiode. As the laser spot 512 ismoving along a wavy path defined by superposition of the fast horizontalscan and slow vertical scan, the FOV moves only vertically, which thesame speed as the slow vertical scan, thus covering the scan line thelaser spot is currently on. Such arrangement may be implemented, forexample, by routing the FOV of the photodiode only through the slowstage of the scanning system 513, but not its fast stage. Yetalternatively, the FOV may be shaped to follow the laser beam in closeproximity without overlapping it (FIG. 67( c)). In this case, the FOVstill moves in sync with the laser spot 512, but since it does notinclude the laser spot itself, the light reflected from the surface ofthe skin does not reach the photodiode. Instead, some portion of thelight which penetrates the body, and, after scattering inside tissues,re-emerges from the skin surface some distance away from the laser spot,forming an afterglow area 515, which is partly overlapped with FOV.Collecting only the scattered light while reducing overall signalstrength, has the advantage of avoiding variations caused by non-uniformreflections from random skin features and may be helpful in discerningdeep veins.

Multiple photodiodes may also be arranged in an array in such way thattheir individual FOVs cover the entire area illuminated by the IR laser.At any given moment, only the signals from one or more photodiodes whoseFOV overlap the laser beam or fall in proximity to it may be taken intothe account.

The photodiodes convert the contrasted infrared image returning from thepatient into an electrical signal. The photodiode board 54 amplifies,sums, and filters the current it receives to minimize noise. The returnsignal of the photodiode engine 53 is differentiated to betterfacilitate discrimination of the contrast edges in the received signalreceived by photodiodes 60 and 61. FIG. 71 (a) represents a typicalsignal collected from photodiodes 60 and 61 and digitized. Local peaks580 correspond to the locations of veins in the patient body. FIG. 71(b) represents the same signal after the differentiation. Sincedifferentiation is known to remove the constant parts of the signal andamplify its changing parts, peaks 580 a can be easily found bycomparison to ground reference (zero signal level of FIG. 71( b)). Thephotodiode board 54 also determines the locations where the infraredlight has the lowest signal reflectivity using a scan system. Theselower reflectivity locations indicate the vein locations.

Signal processing methods other than differentiation, including DigitalSignal Processing (DSP) may be employed as well, such as Fast FourierTransform (FFT), Finite Impulse Response (FIR) and Infinite ImpulseResponse (IIR) filtration. Additionally, more complex image processingalgorithms might be used, for example based on continuity analysis, asthe veins generally form continuous patterns. For example, FIG. 72 showsa few consecutive scan lines crossing a single vein 592. While mostlines produce distinctive signal peaks 590, indicating the veinlocation, in some lines those picks might by masked by noise 591. Still,connecting the vein location points derived from distinctive picksallows the algorithm to establish and display the true location of thevein.

To facilitate the use of DSP algorithms, the electronic circuitry todigitize the signal from the photodiodes and store it subsequently insome form of digital memory might be provided. Consequently, the displayof the vein pattern by the red laser might be delayed with respect tothe acquisition of said pattern with the IR laser. Such delay may varyfrom a small fraction of the time interval needed to scan the entiredisplay area to several such intervals. If necessary, an intentionalmisalignment between the red and IR laser might be introduced, so thered laser can light up or leave dark the areas where the IR laserdetected the lower or higher reflectivity, although the red laser beamwould travel through those areas at different times than the IR laser.

The scan system employed by the apparatus 10 of the present inventionuses a two dimensional optical scanning system to scan both the infraredand visible laser diodes. A dichroic optical filter element 125 in FIG.44 allows laser diodes 63 and 64 to be aligned on the same optical axisand be scanned simultaneously. This allows for a minimal time delay indetecting the infrared reflected signal, and then re-projecting thevisible signal.

The scan system employed by the apparatus 10 of the present inventionhas a horizontal and vertical cycle. Vertical scanning is driven in asinusoidal fashion, and in one embodiment it occurs at 56.6 Hz, which isderived from 29 KHz sinusoidal horizontal scan. The Scan system is alsointerlaced. During a horizontal cycle the projection system is activeonly one half the horizontal scan system and blanked during thealternate half of the scan cycle. On the alternate vertical cycle theblanked and active portion of the horizontal scan is reversed. The topand bottom areas of the scan are blanked as well with a small area atthe top of scan, located behind a mechanical shield for safety, reservedfor execution of a laser calibration activity.

Alternative scan system might be used as well, such as those using asingle scanning mirror deflectable in two orthogonal directions, or twouni-directional mirrors with smaller ratios of horizontal and verticalfrequencies, such that the scan pattern forms a Lissajou figure (Seehttp://www.diracdelta.co.uk/seience/source/l/i/lissajous%20figures/source.html,and for animated figures, http://ibiblio.org/e-notes/Lis/Lissa.htm,which are incorporated herein by reference).

Various mechanical arrangements for scanning mirrors may be used. In oneembodiment (FIG. 68) the mirror 550, made of glass, plastic or silicon,is attached to a free end of a cantilevered torsion fiber 551, made ofglass or other linearly-deformable material, the other end of which isfixed to a base plate 552. A magnet 553, polarized in a directionperpendicular to the fiber, is attached to the fiber between the baseplate and the mirror. A coil 554 may be positioned in close proximity tothe magnet. The coil 554 may be used both for driving the mirror byvirtue of energizing it with AC current, as well as for collecting thepositional feedback by virtue of amplifying the voltage induced in thecoil by magnet's oscillations. Both functions may be accomplishedsimultaneously, for example, by using one half of the mirror'soscillatory cycle for driving and the other half for collectingfeedback. Alternatively, other means of driving the mirror, such asinducing torsional oscillation on the entire base plate by means of apiezo-electric element 555, might be used. The magnet 553 and the coil554 are used exclusively for feedback in this case.

The torsion mode of the fiber 551 may be higher than fundamental,meaning that at least one torsional node, i.e. a cross-section of thefiber which remains still during oscillations, is formed. Such nodesallows for generally higher oscillation frequency at the expense ofgenerally lower oscillation amplitude.

Since high oscillation frequency is desirable to obtain high-resolutionimages at smooth video rates, the linear speed of the mirror's outeredges becomes quite high as well, leading to excessive dust buildupalong those edges. To alleviate this problem, the edges of the mirrormay be smoothed by either removing some mirror material 560 (FIG. 69),or adding a layer of bevel-shaped coating 561 around the edges of themirror.

Non-mechanical scanning systems, such as acousto-optic, electro-optic orholographic might be employed as well.

In a preferred embodiment, each scan line is divided into 1024 pixelsnumbered 0-1023. In pixel range 0-106, red laser 63 is at its threshold,and IR laser 64 is off. The term “threshold”, as applicable to lasers,means an inflection point on the laser Power-Current (P-I) curve, wherethe current becomes high enough for the stimulated emission (aka“lasing”) to begin. This point is marked Ith of FIG. 73, which, whiletaken from the documentation of Sanyo Corp., is representative of thevast majority of laser diodes. In pixel range 107-146, red laser 63 isactive, and IR laser 64 is at its threshold. In pixel range 182-885, redlaser 63 is active, and IR laser 64 is on. In pixel range 886-915, redlaser 63 is active, and IR laser 64 is off. In pixel range 916-1022, redlaser 63 is at its threshold, and IR laser 64 is off. In pixel range0-106, red laser 63 is at its threshold, and IR laser 64 is off.

Projection is accomplished by loading the appropriate compare registersin the complex programmable logic device, or CPLD. The content of theregisters is then compared to the running pixel counter, generating atrigger signal when the content of a register matches the pixel count.The “left” register is loaded with the pixel count of when the lasershould be turned off and the “right” register loaded with the pixelcount of when the laser should be turned back on. The registers shouldbe loaded on the scan line prior to the line when the projection is tooccur. Projection is only allowed during the “Active” part of the redlaser scan, i.e. between pixels 107 and 916, as explained above.

To improve vein visibility it is important to maintain the laser spot ofa proper size on the surface of the patient's skin. This may beaccomplished by fixed laser-focusing optics, or by an auto-focusingsystem which adjusts the beam focusing in response to changes in thedistance to the target.

Certain patient's veins or a portion of their veins might not bedisplayed well or at all. Causes for veins not be displayed include veindepth skin conditions (e.g. eczema, tattoos), hair, highly contouredskin surface, and adipose (i.e. fatty) tissue. The apparatus is notintended to be used as the sole method for locating veins, but should beused either prior to palpation to help identify the location of a vein,or afterwards to confirm or refute the perceived location of a vein.When using the apparatus qualified medical personnel should alwaysfollow the appropriate protocols and practices.

In one embodiment, when the user wishes to operate the apparatus, theuser may apply a perpendicular force to the top surface of the sidebutton 113, or depress power button 112 to power the device. Once thedevice has been powered, the user can turn on the display light 62 bypressing and holding the top surface of the side button 113 for a setamount of time. In a preferred embodiment the photodiode board 54 hasbeen programmed to activate the display light 62 after the user has heldside button 113 for a half second.

Embedded in the user interface board 44 may be firmware, which supportsthe displaying, upon LCD 14, of a menu system (see FIGS. 15-22). Themenu system permits a user to access a plurality of features that theapparatus of the present invention can perform. The user can cyclethrough different display modes that the firmware has been programmed totransmit to the display by tapping the top surface of the side button98. The features embedded in the firmware can include a menu system,menu settings, display status. In one embodiment, the first LCD button110 is programmed to access the menu mode (FIG. 15). One of thosefeatures of the firmware permits labeling or naming of a particularapparatus, as seen in FIG. 20. Such labeling may become advantageous inan environment where a medical service provider utilizes a plurality ofthe apparatus 10, such as in an emergency room. The plurality ofapparatus 10 may be maintained in a corresponding plurality ofrechargeable cradles 5, which may be mounted to a bracket 200, andsecured thereto using fastening means 201, as seen in FIG. 29. Power tothe cradles 5 may be supplied from an adapter 202 plugged into a walloutlet, with a power splitter 203 supplying power to each cradle 5. Eachof the plurality of apparatus 10 in this example may be appropriatelylabeled, “ER1,” “ER2,” . . . .

When the apparatus's 10 display light 62 is activated, the apparatus 10can be used to locate veins. The user can access the scan function bynavigating to it using the keypad 13. The firmware will contain afeature which will allow the user to cycle through display settingsusing a menu system to optimize vein display for the current subject.When the display light 62 is deactivated, the display 14 remainsavailable for viewing status and making configuration settings using themenu system.

1. An apparatus, for use in imaging vein locations of a target skinsurface to aid in venipuncture processes, said apparatus comprising:means for receiving electrical power, for use in powering saidapparatus; a first laser, said first laser configured to emit at least afirst wavelength of light; one or more optical detectors; said one ormore optical detectors each configured to be responsive to said at leasta first wavelength of light; said one or more optical detectorsconfigured to receive a contrasted image from the target skin surfaceformed by reflected light at said first wavelength being amplitudemodulated according to differential amounts of absorption and reflectionbetween subcutaneous veins and surrounding tissue therein, and said oneor more optical detectors further configured to convert said receivedcontrasted image into a signal; a second laser; said second laserconfigured to emit at least a second wavelength of light; said at leasta second wavelength being different than said at least a firstwavelength of light; a microcontroller; a user interface boardcomprising: one or more push buttons; firmware, said firmware configuredto permit said one or more buttons to select one or more settings forsaid apparatus, and to permit said selected one or more settings to bestored in a memory, said one or more settings comprising one or morevein visualization settings; and means to indicate said selectedsetting; and electronic circuitry; said electronic circuitry configuredto receive said signal from said one or more optical detectors and tooutput said signal to said second laser, said electronic circuitryconfigured to cause said second laser to use said signal to emit said atleast a second wavelength of light to project the vein locations of saidcontrasted image onto the target skin surface in accordance with saidselected setting of said vein visualization settings to be optimized forthe target skin surface.
 2. The apparatus of claim 1, wherein saidfirmware and said means to indicate said selected setting are eachfurther configured to permit said means to indicate to also indicate oneor more of a menu system comprising one or more menu settings, aconfiguration of said apparatus, and a status of said apparatus.
 3. Theapparatus of claim 2, wherein said firmware and said menu settings areconfigured to permit changing of configuration settings comprising oneor more of: a default setting for said one or more vein visualizationsettings; a vein display time-out interval; a backlighting intensity; avolume of a speaker; and a language setting.
 4. The apparatus of claim3, wherein said speaker is configured to generate a distinctive soundwhen a function is activated or an event occurs, said event comprising alow battery charge.
 5. The apparatus of claim 1, wherein said electroniccircuitry comprises a USB chip configured to receive an update to saidfirmware.
 6. The apparatus of claim 1, wherein said one or more opticaldetectors comprises a pair of photodiodes.
 7. The apparatus of claim 1,further comprising a photodiode board, said photodiode board beingconfigured to amplify, sum, and filter said signal received from saidpair of photodiodes to minimize noise for improved discrimination of theedges of said vein locations in said contrasted image.
 8. The apparatusof claim 1, further comprising a scan system configured to scan a beamof said first wavelength of light emitted from said first laser and toscan a beam of said second wavelength of light emitted from said secondlaser onto the target skin surface.
 9. The apparatus of claim 7, whereinsaid scan system is configured to scan said beams of said first andsecond wavelengths of light from said first and second lasers using ahorizontal scan and a vertical scan.
 10. The apparatus of claim 9,wherein said scan system comprises a scan system from the group of scansystems consisting of: a single scanning mirror deflectable in twoorthogonal directions; and two uni-directional scanning mirrors.
 11. Theapparatus of claim 10, further comprising a dichroic optical filterelement configured to align said beams of said first and secondwavelengths of light from said first and second lasers on the sameoptical axis for simultaneous scanning.
 12. The apparatus of claim 11further comprising a respective lens for said first and secondphotodiodes, said respective lenses configured to reduce the field ofview of said first and second photodiodes, respectively, to have anextent being substantially the same as field scanned by said scansystem.
 13. The apparatus of claim 1, wherein said first laser isconfigured to emit an infrared wavelength of light and said second laseris configured to emit a red wavelength of light.
 14. The apparatus ofclaim 13 wherein said second laser is configured to emit light at awavelength of 642 nm, and said first laser is configured to emit lightat a wavelength of 785 nm.
 15. The apparatus of claim 1, wherein saidone or more buttons comprise a first display button, a second displaybutton, and a power button.
 16. The apparatus of claim 1, furthercomprising one or more heat sinks and one or more fans configured tocool said first and second lasers.
 17. The apparatus of claim 1 furthercomprising a venipuncture needle with a material coating configured toabsorb a detectable amount of said first wavelength of light from saidfirst laser, to be detectable in said contrasted image by said one ormore optical detectors; and wherein said firmware is configured todetect said coated venipuncture needle beneath the target skin surfacein said contrasted image and thereby project said image of said coatedneedle onto the target skin surface.
 18. The apparatus of claim 17,wherein said biomedical material coating comprises a glucose coating.19. The apparatus of claim 1, wherein said electronic circuitry isconfigured for projection of said contrasted image as a positive imageor a negative image, wherein said negative image comprises said light ofsaid second laser being projected outside of said vein locations, andsaid positive image comprises said light of said second laser projectedonly on said vein locations.
 20. The apparatus of claim 1, wherein saidelectronic circuitry comprises a complex programmable logic device(CPLD), said CPLD comprising a first and a second compare register, andsaid CPLD configured to load a pixel count into said first register forsaid second laser to project said contrasted image, and said CPLDconfigured to load a pixel count into said second register for saidfirst laser to emit said first wavelength of light.
 21. An apparatus,for use in imaging vein locations on a target skin surface to aid invenipuncture processes, said apparatus comprising: means for receivingelectrical power; a first laser, said first laser configured to emit afirst wavelength of light; one or more optical detectors; said one ormore optical detectors each configured to be responsive to said a firstwavelength of light; said one or more optical detectors configured toreceive a contrasted image from the target skin surface formed byreflected light at said first wavelength being amplitude modulatedaccording to differential amounts of absorption and reflection betweensubcutaneous veins and surrounding tissue therein, and said one or moreoptical detectors further configured to convert said received contrastedimage into a signal; a second laser; said second laser configured toemit a second wavelength of light; said second wavelength beingdifferent than said first wavelength of light; a microprocessor; a userinterface board comprising: one or more push buttons; firmware, saidfirmware configured to permit said one or more buttons to select one ormore settings for said apparatus, and to permit said selected one ormore settings to be stored in a memory, said one or more settingscomprising one or more vein visualization settings; and means toindicate said selected setting; and electronic circuitry; saidelectronic circuitry configured to receive said signal from said one ormore optical detectors and to output said signal to said second laser,said electronic circuitry configured to cause said second laser to usesaid signal to emit said second wavelength of light to project the veinlocations of said contrasted image onto the target skin surface inaccordance with said selected setting of said vein visualizationsettings to be optimized for the target skin surface.